Hey guys and girls, I have been unable to boot my machine for that last few days. I am intending to take it to a technician to have it looked at but that is still a whole weekend away and i need to know (for my soul) the likely way the diagnosis is going to go. So here is the run down:

My Pro was functioning as normal, (no clicking whirring or troubling sounds beforehand), attempted to open a email attachment to no success, closed the window and tried again - laptop froze, after about a minute of no success i held the power button down and shut it off. Left it for a few seconds and pressed the power button, screen flickers to life, start up sound is heard and the screen goes to its grey colour... and then, nothing.

This is now the default response to powering it up. This is accompanied by a long low beep sound that is continuous, (sometimes the beep runs constantly until i force power it down or it stops after a while, this is usually when i wait for the install disc to eject). as well as the beep there is a slight clicking sound (HD heads trying to move?) and a inconsistant whirring sound (possibly the fan starting? but likely the hard drive spinning up?).

-Attempted fixes- (all to no avail or different start up sequence, unless mentioned)

Safe boot (holding shift key)

NVRAM reset (Command, opt, P, R) *machine boots twice, first time and then again upon reset.

Start from install disc (holding C Key) -Disc is inserted on a grey screen, machine reset, then rebooted, no different start up, I then hold down the eject key for about 30sec and the disc finally ejects (this has happened on its own accord at one point)

I have tried to reset the SMC and no change of sequence

My machine has upgraded RAM(from 4GB Stock to 8GB Crucial), i have replaced the sticks with the stock RAM, no different result and now it has been replaced with the 2x4GB Crucial sticks.

And this is where I am at now.

First thought is the hard drive has seized itself, i opened it up and had a look but the platters are still spinning fine so possibly the heads are jammed. However its inability to boot from the disc makes me think there may be something else?

As I say I am intending to take it to be looked at, but I want to get my head around the likely issues, I can accept a simple hard drive failure (albeit bitterly as i will lose about a month and a halfs worth of data/research) but I am concerned there may be other issues (the logic board).

Often Macs get stuck 'looking' for the hard drive, either because of a faulty hard drive flex cable or faulty hard drive itself.A grey screen is shown, before finally 'timing out' and displaying either the prohibited ('no entry') symbol or flashing folder with question mark. The whole time out procedure can take a few minutes, which is why people commonly assume that it has stopped.

Next step would be to unplug the hard drive cable (lifts straight up from the Logic Board) and see if the machine immediately (within 15-20 seconds) shows the flashing question mark folder instead of getting stuck at the grey screen.Other way is to hold the Option key once unplugging the cable - obviously no bootable devices will be found, but there will likely be a mouse pointer showing at the boot menu (another grey screen). If the machine is 'stuck' looking for a bootable device, it won't even show the mouse.